Electrical connectivity for circuit applications

ABSTRACT

According to example configurations herein, a leadframe includes a first conductive strip, a second conductive strip, and a third conductive strip disposed substantially adjacent and substantially parallel to each other. A semiconductor chip substrate includes a first array of switch circuits disposed adjacent and parallel to a second array of switch circuits. Source nodes in switch circuits of the first array are disposed substantially adjacent and substantially parallel to source nodes in switch circuits of the second array. When the semiconductor chip and the leadframe device are combined to form a circuit package, a connectivity interface between the semiconductor chip and conductive strips in the circuit package couples each of the source nodes in switch circuits of the first array and each of the multiple source nodes in switch circuits of the second array to a common conductive strip in the leadframe device.

RELATED APPLICATIONS

This application is a divisional application of earlier filed U.S.patent application Ser. No. 12/830,828 entitled “ELECTRICAL CONNECTIVITYFOR CIRCUIT APPLICATIONS,” filed on Jul. 6, 2010, the entire teachingsof which are incorporated herein by this reference.

BACKGROUND

Surface-mount technology (SMT) provides a way of interconnectingelectronic circuit components with each other. For example, according tosuch technology, electronic devices are specifically packaged formounting directly on a respective surface of a printed circuit board.Because of the advantages associated with surface mount technology suchas smaller part size, surface mount technology has, to a large extent,replaced through-hole technology in which wire leads of components arefitted and soldered into holes of a printed circuit board to provideconnectivity.

Surface mount devices come in a variety of styles. For example, asurface mount device can have relatively small leads or no leadsextending from the package at all. Because a surface mount device hasrelatively small leads or no leads at all, a surface mount device isusually smaller than its through-hole counterpart. The surface mountdevice may have short pins or leads of various styles, flat contacts, amatrix of solder balls (such as Ball Grid Arrays), or terminations onthe body of the component.

One type of electronic circuit that can be packaged in a surface mountdevice is a so-called integrated circuit or semiconductor chip. Theintegrated circuit can provide a variety of functionality depending onhow the integrated circuit (e.g., chip) is designed. For example, in aspecific application, an integrated circuit can include one or morearrays of small transistors that are interconnected in parallel withrespect to each other based solely on metal layers (e.g., conductivepaths) in the integrated circuit. Connecting multiple small transistorsof an integrated circuit in parallel via the corresponding layers ofmetal effectively can produce a single transistor supporting highcurrent drive and low impedance switching capability.

In certain other applications, transistors can be obtained as discretecomponents (e.g., individual electrical parts) and connected in parallelwith each other via respective traces on a circuit board. As is the casefor multiple transistors connected in parallel via the metal layers inan integrated circuit, a set of multiple transistors in parallel witheach other on a circuit board can provide higher current sinking andsourcing capability.

BRIEF DESCRIPTION

Conventional applications such as those as discussed above can sufferfrom a number of deficiencies. For example, a conventional switchcircuit derived from an array of small transistors in an integratedcircuit can require tens, hundreds, or even more transistors connectedin parallel via metal layers in the integrated circuit to produce asingle effective, functional transistor. Connecting multiple transistorsin parallel can be quite complex due to the number of individualtransistors that must be interconnected. For example, each transistor inthe array can have a corresponding gate, source, and drain. To connectthe transistors in parallel and form a single effective transistordevice, the integrated circuit must connect all of the gates to eachother, all of the sources to each other, and all of the drains to eachother. Providing conventional connectivity to connect a set oftransistors in parallel, according to conventional techniques, requiresa complex metal interconnect potentially including many layers.

As is known, the transistors in such a device as well as correspondingmetal interconnect layers of the integrated circuit are very small andthus difficult and expensive to manufacture. Even if it is possible tomanufacture such devices, the complexity of the metal interconnectlayers of the integrated circuit means that the device is more likelyprone to failure or low manufacture yields. Additionally, when used, themetalization layers in an integrated circuit are usually not thickenough to provide a very low impedance path. This results in unwantedlosses.

Embodiments herein deviate with respect to conventional applications.For example, embodiments herein are directed to a unique way ofproviding interconnectivity of circuitry such as transistors in aleadframe device.

More specifically, one embodiment herein includes a circuit packageincluding a leadframe, a semiconductor chip, and a connectivityinterface. As its name suggests, the connectivity interface providesconnections between the semiconductor chip and the leadframe. Forexample, in one embodiment, the leadframe comprises: a first conductivestrip, a second conductive strip, and a third conductive strip disposedsubstantially adjacent and parallel to each other. The semiconductorchip substrate can include a first array of switch circuits disposedadjacent and parallel to a second array of switch circuits. Primarynodes such as source nodes in switch circuits of the first array can bedisposed substantially adjacent and substantially parallel to primarynodes in switch circuits of the second array.

In a further specific embodiment, each array of switch circuits caninclude a row of source nodes and a row of drain nodes. The row of thesource nodes in the first array and the row of source nodes in thesecond array can be disposed between the row of drain nodes in the firstarray and the row of drain nodes in the second array. The connectivityinterface of the circuit package couples each of the source nodes inswitch circuits of the first array and each of the multiple source nodesin switch circuits of the second array to a single conductive strip suchas the second conductive strip. The second conductive strip cantherefore be a common source node for source nodes in transistors of thefirst array and transistors of the second array.

When the leadframe is installed on a circuit board, the secondconductive strip of the circuit package provides connectivity betweenthe source nodes and a connection point on to a host substrate such as aprinted circuit board. Disposing the row of source nodes in the firstarray next to the row of source nodes in the second array can reduce anoverall pin or pad count of the circuit package as parallel and adjacentrows of source nodes in relatively close proximity to each other can beconnected to a common conductive strip in the leadframe as opposed tomultiple conductive strips in the leadframe. Thus, when the leadframe isinstalled on a circuit board, the second conductive strip of the circuitpackage provides connectivity between the source nodes in the first andsecond arrays and a connection point on a host substrate such as aprinted circuit board.

In further embodiments, the connectivity interface in the circuitpackage can provide connectivity between the drain nodes in the firstarray and the first conductive strip. Thus, the first conductive stripcan be a common drain node. When the leadframe is installed on a circuitboard, the first conductive strip of the circuit package providesconnectivity between the drain nodes in the first array and a connectionpoint on the host substrate.

Also, the connectivity interface in the circuit package can provideconnectivity between the drain nodes in the second array and the thirdconductive strip. Thus, the third conductive strip also can be a commondrain node. When the leadframe is installed on a circuit board, thethird conductive strip of the circuit package provides connectivitybetween the drain nodes in the second array and a connection point onthe host substrate. By way of a non-limiting example, prior to makingthe connection between the array of switch circuits and the conductivestrips, each of the source nodes can be electrically isolated from eachother, each of the drain nodes in a respective transistor circuit tilecan be electrically isolated from each other, etc. Subsequent to makingconnection of the electrical circuit with the connectivity interface inthe leadframe, the respective conductive strip in the leadframeelectrically connects the source nodes together. Accordingly,embodiments herein include a way of utilizing a connectivity interfacein a leadframe to provide connectivity between nodes of an electricalcircuits in lieu of having to provide such connectivity at, for example,an on-chip metal interconnect layer of an integrated circuit device.

As briefly discussed above, in addition to a first connectivityinterface connecting the circuit to one or more conductive strip, thecircuit package as discussed herein can also include a secondconnectivity interface (such as pins, pads, etc.) for electricallyattaching the conductive strips in the circuit package to a hostsubstrate such as a circuit board.

Although any reasonable configuration is possible, according to oneembodiment, the first connection interface resides on a first facing ofthe leadframe and the second connectivity interface resides on a secondfacing of the leadframe. The conductive strips in the leadframe providepaths on which to connect nodes of the semiconductor chip to nodes on arespective circuit board.

Embodiments herein further include a packaged circuit device comprising:a conductive strip and a semiconductor chip substrate including a firstarray of switch circuits disposed substantially adjacent andsubstantially parallel to a second array of switch circuits. A firstconnectivity interface of the conductive strip couples switch circuitsin the first array and switch circuits in the second array to theconductive strip. A second connectivity interface of the conductivestrip can be configured to electrically couple the conductive strip inthe packaged circuit to an electrical node of a host circuit substrate.

Embodiments herein further include a novel integrated circuit device.The integrated circuit device can comprise a first array of switchcircuits and a second array of switch circuits. The first array ofswitch circuits can be disposed on a semiconductor chip substrate. Eachswitch circuit in the first array can include a source node and a drainnode. The second array of switch circuits also can be disposed on thesemiconductor chip substrate. Each switch circuit in the second arraycan include a source node and a drain node. Source nodes in switchcircuits of the first array can be disposed on the semiconductor chipsubstrate to be adjacent and in close proximity to source nodes inswitch circuits of the second array. Accordingly, the source nodes inthe first array and the second array can be easily connected to a commonconnectivity region of a conductive strip on the leadframe device.

In yet further embodiments as discussed herein, an integrated circuitdevice can include: a semiconductor layer, multiple interconnect layers,a first conductive layer and a second conductive layer. Thesemiconductor conductive layer can be fabricated to include multipletransistors. The multiple interconnect layers connect the multipletransistors in parallel with each other. The first conductive layerelectrically can be electrically coupled to the multiple transistors viathe multiple interconnect layers. The first conductive layer can be amaterial having a first resistivity. The second conductive layer can beelectrically coupled to the first conductive layer. The secondconductive layer can be a material having a second resistivity, thesecond resistivity being less than the first resistivity. Because thesecond conductive layer is a lower resisitivity, it can provide a betterconductive path between, for example, transistors in the semiconductorlayer and a conductive strip in the leadframe to which the conductivelayers are electrically connected.

These and other more specific embodiments are disclosed in more detailbelow.

The embodiments as described herein are advantageous over conventionaltechniques. For example, the leadframe device according to embodimentsherein provides unique connectivity in a circuit package, alleviatingthe complexity of connectivity provided in metal interface layer(s) ofan integrated circuit device.

It is to be understood that the system, method, apparatus, etc., asdiscussed herein can be embodied strictly as hardware, as a hybrid ofsoftware and hardware, or as software alone such as within a processor,or within an operating system or a within a software application.Example embodiments of the invention may be implemented within productsand/or software applications such as those developed or manufactured byCHiL Semiconductor of Tewksbury, Mass., USA.

As discussed above, techniques herein are well suited for use inleadframe packaging applications. However, it should be noted thatembodiments herein are not limited to use in such applications and thatthe techniques discussed herein are well suited for other applicationsas well.

Additionally, note that although each of the different features,techniques, configurations, etc., herein may be discussed in differentplaces of this disclosure, it is intended, where appropriate, that eachof the concepts can optionally be executed independently of each otheror in combination with each other. Accordingly, the one or more presentinventions as described herein can be embodied and viewed in manydifferent ways. Also, note that this preliminary discussion ofembodiments herein purposefully does not specify every embodiment and/orincrementally novel aspect of the present disclosure or claimedinvention(s). Instead, this brief description only presents generalembodiments and corresponding points of novelty over conventionaltechniques. For additional details and/or possible perspectives(permutations) of the invention(s), the reader is directed to theDetailed Description section and corresponding figures of the presentdisclosure as further discussed below.

As further discussed below, different embodiments herein support: 1)reducing a pin count of leadframe semiconductor chip, 2) use ofconductive paths in a leadframe device to provide interconnects betweentransistor modules to enable the use of thick top layer metal (in otherlayers of a semiconductor device) to be used for control purposes suchas a low impedance gate interconnect that enables a centralized drivercircuit which simplifies a leadframe design, further enhancingscalability; 3) size matching of chip transistor modules with respect toa leadframe strip pitch in a leadframe device; 4) unique connectivitybetween circuits on an integrated circuit and circuit board to which theleadframe is attached; and so on.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features, and advantages of theinvention will be apparent from the following more particulardescription of preferred embodiments herein, as illustrated in theaccompanying drawings in which like reference characters refer to thesame parts throughout the different views. The drawings are notnecessarily to scale, with emphasis instead being placed uponillustrating the embodiments, principles, concepts, etc.

FIG. 1 is an example side view diagram of a leadframe package andrespective leadframe package components according to embodiments herein.

FIG. 2 is an example 3-D diagram illustrating coupling of an electricalcircuit to conductive strips in a corresponding leadframe according toembodiments herein.

FIG. 3 is an example 3-D diagram illustrating coupling of an electricalcircuit to conductive strips in a corresponding leadframe according toembodiments herein.

FIG. 4A is an example diagram of an electrical circuit includinguniquely oriented tiles of transistors according to embodiments herein.

FIG. 4B is an example diagram of electrical circuits to be cut from asemiconductor wafer according to embodiments herein.

FIG. 5 is an example diagram of a tile including arrays of multipletransistors connected in parallel according to embodiments herein.

FIG. 6 is an example diagram illustrating connectivity between each ofmultiple transistor tile circuits and a respective conductive path orconductive strip in a leadframe device according to embodiments herein.

FIG. 7 is an example diagram illustrating a model of an array ofinterconnected transistors according to embodiments herein.

FIG. 8 is an example diagram illustrating pads on a leadframe packageaccording to embodiments herein.

FIG. 9 is a see-through diagram illustrating connectivity of anelectrical switching circuit, through a leadframe package, to a hostsubstrate on which the leadframe is mounted according to embodimentsherein.

FIG. 10 is a diagram illustrating switching functionality provided by anexample leadframe device and related components according to oneembodiment herein.

FIG. 11 is a diagram illustrating packaging of a circuit and relatedcomponents in an example leadframe device according to embodimentsherein.

FIGS. 12-15 are flowcharts illustrating example methods supportingcreation of a circuit package and integrated circuit according toembodiments herein.

FIG. 16 is an example side view diagram illustrating layering in acircuit according to embodiments herein.

FIG. 17 is an example top view diagram illustrating layering in circuitaccording to embodiments herein.

FIG. 18 is an example top view diagram illustrating layering in circuitaccording to embodiments herein.

FIG. 19 is an example top view diagram illustrating layering in circuitaccording to embodiments herein.

FIG. 20 is an example top view diagram illustrating layering in circuitaccording to embodiments herein.

FIGS. 21-23 are flowcharts illustrating example methods of creating acircuit according to embodiments herein.

DETAILED DESCRIPTION

FIG. 1 is an example diagram illustrating interconnectivity of anelectrical circuit 120, leadframe device 190, and substrate 170according to embodiments herein.

As shown, one embodiment herein includes a leadframe device 190comprising a connection interface 110-1. The connection interface 110-1can be configured for electrically attaching or coupling electricalcircuit 120 such as a semiconductor chip, integrated circuit, etc., tothe leadframe device 190.

The leadframe device 190 includes one or more conductive paths includingconductive path 140-2. The conductive path 140-2 (e.g., conductivestrip) has a contact region on facing 150-1 of the leadframe device 190and provides a contact region in which to make an electrical connectionbetween electrical node 125-1 of the electrical circuit 120 andelectrical node 125-2 (e.g., a source node, drain node, etc.) of theelectrical circuit 120. Electrical node 125-1 can be an exposed metallicregion or contact on a facing of the electrical circuit 120.

In one embodiment, prior to making the connection between the electricalnodes 125-1, 125-2, . . . of electrical circuit 120 and the contactregion of the conductive path 140 in the leadframe device 190, theelectrical node 125-2 and the electrical node 125-1 are electricallyisolated from each other. In other words, by way of a non-limitingexample, and in accordance with one embodiment, the electrical nodes 125are not electrically connected with respect to each other by virtue of ametal interconnect on the electrical circuit 120.

Subsequent to making connection of the electrical circuit 120 with theleadframe device 190 via conductive bridge elements 130, the conductivepath 140-1 of the leadframe device 190 electrically connects theelectrical node 125-2 and the electrical node 125-1 together. Bridgeelements 130 can be pillars, posts, or other suitable shape formed fromconductive material.

In one embodiment, the conductive bridge element 130-1 electricallyconnects the electrical node 125-1 to the conductive path 140-2, theconductive bridge element 130-2 electrically connects the electricalnode 125-2 to the conductive path 140-2, and so on.

As mentioned, the conductive bridge element 130 can take on any of anumber of different forms. For example, in one embodiment, theconductive bridge element 130 is a pillar made of conductive material.

The pillar or other suitably shaped bridge element 130 can be formed ona surface of the electrical circuit 120 by depositing a metal layer onthe electrical circuit 120 and then etching away a portion of thedeposited metal layer. As shown, circuit 120 can include multipleelectrical nodes 125 that are initially electrically isolated from eachother but which became attached together via a low impedance path afternodes such as 125-1, 125-2, are electrically connected to conductivepath 140-1.

In one embodiment, the conductive path 140-2 is a conductive stripdisposed in the leadframe device 190 to electrically connect theisolated nodes of circuit 120 together as well as connect such nodes tosubstrate 170. The leadframe device 190 can include one or moreconductive strips disposed as discussed herein and parallel to eachother.

In accordance with another embodiment, the bridge elements 130 orpillars are plated up after a mask is applied. This is a selectiveplating process as opposed to a selective etching. Either approach couldbe used to produce the bridge elements 130.

In further embodiments, note that a conductive material such as soldercan be used to connect the pillars (conductive bridge elements) to arespective conductive strip or conductive path 140-2 in the leadframedevice 190.

In one embodiment, the conductive bridge elements 130 are made fromcopper, although any suitable metal or conductive material can be usedto provide such functionality.

Thus, in an example embodiment, the electrical node 125-1 can beelectrically coupled to a pillar of conductive material for connecting afirst portion of the electrical circuit 120 to the conductive path 140-2of the leadframe device 190. The electrical node 125-2 can beelectrically connected to a second pillar of conductive material forconnecting a second portion of the electrical circuit 120 to theconductive path 140-2 of the leadframe device 190. Again, the conductivebridge elements 130 can be made of copper or other suitable conductivematerial.

According to other alternative embodiments, note that the conductivebridge elements 130 can be solder balls that connect respectiveelectrical nodes 125 of the electrical circuit 120 to the conductivepath 140-2.

The electrical circuit 120 can be an integrated circuit such as asemiconductor chip. The electrical nodes 125 can emanate from a singleelectrical circuit 120 fabricated on a common semiconductor substrate.The electrical circuit 120 can thus be a semiconductor chip cut from awafer.

In alternative embodiments, the electrical circuit 120 can include anumber of semiconductor chips that are packaged into the same leadframepackage 100.

The embodiments in FIG. 1 illustrate a technique of utilizing aleadframe device 190 or leadframe package to provide off-chipconnectivity between electrical nodes 125 of an electrical circuit 120in lieu of having to provide such connectivity at, for example, a metalinterconnect layer of the integrated circuit device. In other words, theconductive strips or conductive paths 140 in the leadframe device 190can provide connectivity of two or more circuits in the electricalcircuit 120. As will be discussed later in this specification,connectivity provided by the leadframe device can be used to connect, inparallel, two or more electrically isolated circuits in the electricalcircuit 120.

As shown, the leadframe device 190 can also include a second connectioninterface 110-2 for attaching the leadframe device 190 to a substrate170 such as a printed circuit board, flex-board, etc. Conductive bridgeelement 160-1 such as solder can provide electrical connectivity betweenthe contact element 345-2 (e.g., surface pad) of conductive path 140-2and a respective one or more traces on the substrate 170.

As shown, contact elements 345 and conductive paths 140 in the leadframedevice 190 can be separated from each other via electricallynon-conductive material such as a plastic filler of the leadframepackage 100. The cross-hatched region in the side view of the leadframedevice indicates non-conductive material.

To summarize the details of leadframe device 190 as shown in FIG. 1,although any reasonable configuration is possible, according to oneembodiment, the first connection interface 110-1 resides on a firstfacing 150-1 of the leadframe device 190 and the second connectivityinterface 110-2 resides on a second facing 150-2 of the leadframe device190. By way of a non-limiting example, the first facing 150-1 and thesecond facing 150-2 of the leadframe device 190 can be disposed onopposite sides of the leadframe device 190 with respect to each other,adjacent sides of the leadframe, same side of the leadframe, etc.

One way to produce the leadframe device 190 is to start out with a slabof metal, such as copper, of appropriate thickness. The copper can beetched or machined to remove metal between the conductive paths 140 orlengths of conductive strips so that each of the conductive paths 140are electrically independent of each other. In other words, according toone embodiment, the conductive paths 140 in leadframe device 190 neednot be electrically connected to each other internal to the leadframedevice 190.

Further machining can be performed at axial ends of the conductive paths140 to fit the conductive paths 140 within the leadframe device 190.Since it may be desirable to have spaced surfaces, as in related FIG. 8(top down view), portions of each of one or more of the conductive paths140 on facing 150-2 can be etched and filled in with a non-conductivematerial such as plastic so that pads or contact elements are spaced andelectrically isolated from each other.

A non-conductive material, such as plastic, can be used to fill inbetween the conductive paths 140 and above and around circuit 120 so asto produce package 100 and protect the electrical circuit from adverseenvironmental conditions.

Note that the inclusion of a respective contact element 345 (or pads ofthe leadframe device 190) on each of one or more of the conductive paths140 is shown by way of non-limiting example only and that a respectiveconductive path need not include a surface in which to attach to a hostsubstrate 170. In other words, the conductive path 140-2 or the like mayprovide connectivity between nodes of the electrical circuit 120 withoutfeet or a pad area for connecting the nodes to a host circuit board.Accordingly, the respective conductive path can be used as a way ofconnecting nodes of electrical circuit 120 at a layer other than in ametalization layer of an integrated circuit such as circuit 120. In thislatter embodiment, when the leadframe device 190 is attached to a hostsubstrate 170, the respective conductive path does not attach to thesubstrate.

FIG. 2 is an example 3-D diagram illustrating how an electrical circuit120 is coupled to a leadframe device 190 according to embodimentsherein.

As shown, the exposed side of electrical circuit 120 having exposedelectrical nodes 125 (e.g., electrical node 125-1, electrical node125-2, etc.) is attached to the facing 150-1 of the leadframe device190.

In one embodiment, the electrical circuit 120 is a substantiallyplanar-shaped device (such as an integrated circuit, semiconductordevice, etc.) including multiple independent circuits 210 (e.g., circuit210-1, circuit 210-2, circuit 210-3, circuit 210-4, circuit 210-5,circuit 210-6, . . . ) spread out about a surface of the electricalcircuit 120 (e.g., planar shaped device).

Each circuit 210 can represent a transistor tile circuit having at leasta source node and a drain node. The transistor tile circuit can comprisemultiple individual transistors connected in parallel with each othervia an interconnect layer associated with the circuit tile.

A size associated with leadframe device 190 and corresponding electricalcircuit 120 is highly scalable. For example, a number of rows and/orcolumns of circuits 210 residing on electrical circuit 120 and connectedin parallel can be varied to create switches or transistor tiles havingdifferent sinking/sourcing capabilities. In such embodiments when therow and/or columns of circuits 210 is adjusted, the size of leadframedevice 190 and number of conductive paths 140 in the leadframe device190 can be adjusted to match the number of rows and columns of circuits210 of electrical circuit 120. An example of adjusting rows and columnsof circuits 210 is shown and discussed with respect to FIG. 4B.

Referring again to FIG. 2, each of the electrical circuits 210 ofcircuit 120 can have one or more inputs and/or one or more outputs thatare electrically independent of each other. For example, in furtheranceof the embodiment as discussed above, electrical circuit 120 can be anarray of switch tiles (e.g., circuits 210), each of which has arespective source node and drain node that are not initially attached tosources and drains of any of the other electrical circuits 210 inelectrical circuit 120. In other words, the respective source nodes anddrain nodes of each circuit 210 can be electrically isolated from eachother except for the electrical connection provided by the conductivepath 140-2 in the leadframe device 190 when so connected. Thus, in oneexample embodiment, each of the conductive paths 140 is electricallyindependent until the leadframe device 190 is electrically attached to acircuit board substrate. As discussed later in this specification, thecircuit substrate (to which the leadframe device 190 is attached) caninclude additional conductive paths that provide connectivity amongstthe conductive paths 140 in the leadframe device 190.

In one embodiment, each of the circuits 210 is a switch circuit as willbe discussed later in this specification. Connection of the circuits 210to the conductive paths 140 connects the circuits 210 in parallel. Forexample, circuits 210-1, 210-2, and 210-3 can be connected in parallelwith each other when respective source nodes S₁₁, S₁₂, and S₁₃areconnected to conductive path 140-1 and drain nodes D₁₁, D₁₂, and D₁₃ areconnected to conductive path 140-2 as discussed below. A common gatesignal can be connected to drive respective gate nodes of the circuits210 connected in parallel.

Contact element 345-1 or exposed surface of the conductive path 140-1(e.g., one or more surfaces on facing 150-2 of leadframe device 190)provides connectivity with respect to a substrate such as a printedcircuit board or other interconnecting device.

The conductive paths 140 (e.g., conductive path 140-1, conductive path140-2, conductive path 140-3, conductive path 140-4, etc.) can provideconnectivity between the multiple electrically independent circuits 210and, optionally, provide connectivity through the leadframe device 190to the substrate 170. For example, as shown, the facing of electricalcircuit 120 having exposed node contacts (e.g., S₁₁, S₁₂, . . . , D₁₁,D₁₂, . . . ) can be pressed or moved into communication of the facing150-1 of the leadframe device 190 to connect the electrical nodes 125(e.g., node S₁₁, S₁₂, . . . , D₁₁, D₁₂, . . . ) to correspondinglocations on the conductive paths 140 as indicated.

More specifically, when electrical circuit 120 is moved intocommunication with facing 150-1 of the leadframe device 190 as shown,electrical node 125-2 (e.g., source node S₁₁) of circuit 210-1 comes incontact with the location labeled S₁₁ on conductive path 140-1;electrical node 125-1 (e.g., source node S₁₂) of circuit 210-2 comes incontact with the location labeled S₁₂ on conductive path 140-1;electrical node labeled source node S₁₃ in circuit 210-3 comes incontact with the location labeled S₁₃ on conductive path 140-1; and soon. Thus, the conductive path 140-1 of leadframe device 190 can provide“off-chip” connectivity with respect to a first set of electrical nodesin the electrical circuit 120.

In accordance with the above embodiment, when electrical circuit 120 ismoved in communication with facing 150-1, electrical node labeled drainnode D₁₁ of circuit 210-1 comes in contact with the location labeled D₁₁on conductive path 140-2; electrical node labeled drain node D₁₂ ofcircuit 210-2 comes in contact with the location labeled D₁₂ onconductive path 140-2; electrical node labeled drain node D₁₃ in circuit210-3 comes in contact with the location labeled D₁₃ on conductive path140-1; and so on.

Thus, the conductive path 140-2 of leadframe device 190 can beconfigured to provide off-chip connectivity with respect to a second setof electrical nodes in the electrical circuit 120.

Additionally, when electrical circuit 120 is seated onto facing 150-1,electrical node labeled drain node D₂₁ of circuit 210-4 comes in contactwith the location labeled D₂₁ on conductive path 140-2; electrical nodelabeled drain node D₂₂ of circuit 210-5 comes in contact with thelocation labeled D₂₂ on conductive path 140-2; electrical node labeleddrain node D₂₃ in circuit 210-6 comes in contact with the locationlabeled D₂₃ on conductive path 140-2; and so on. Thus, the conductivepath 140-2 of leadframe device 190 can be configured to provide off-chipconnectivity amongst a row of drain nodes in a first array of circuitsincluding circuits 210-1, 210-2, and 210-3 as well as a row of drainnodes in a second array of circuits including circuits 210-4, 210-5, and210-6.

Additionally, when electrical circuit 120 is moved in communication withfacing 150-1, electrical node labeled drain source node S₂₁ of circuit210-4 comes in contact with the location labeled S₂₁ on conductive path140-3; electrical node labeled source node S₂₂ in circuit 210-5 comes incontact with the location labeled S₂₂ on conductive path 140-3;electrical node labeled source node S₂₃ in circuit 210-6 comes incontact with the location labeled S₂₃ on conductive path 140-3; and soon. Thus, even before mounting of the leadframe device 190 to a circuitboard, the conductive path 140-3 of leadframe device 190 can provide“off-chip” connectivity with respect to a row of source nodes.

In further embodiments, it can be seen that at least a portion of eachrespective conductive path 140 in the leadframe device 190 can besubstantially orthogonal with respect to a plane of the planar-shapeddevice (e.g., electrical circuit 120) on which the multiple circuits 210reside. In other words, according to one embodiment, the conductivepaths provide connectivity to a host substrate in a direction orthogonalto a plane of the electrical circuit 120 to a host substrate.

Thus, according to FIG. 2, a circuit package can include a leadframedevice 190. The leadframe device 190 can include a first conductivestrip (e.g., conductive path 140-1), a second conductive strip (e.g.,conductive path 140-2), and a third conductive strip (e.g., conductivepath 140-3) disposed substantially adjacent and substantially parallelto each other. The electrical circuit 120, such as a semiconductor chipsubstrate, can include a first array of switch circuits (e.g., acombination of circuits 210-1, 210-2, and 210-3) disposed adjacent andparallel to a second array of switch circuits (e.g., a combination ofcircuits 210-4, 210-5, and 210-6.

Drain nodes (D₁₁, D₁₂, and D₁₃) in switch circuits of the first arrayare disposed to face and be substantially adjacent and substantiallyparallel to drain nodes (D₂₁, D₂₂, and D₂₃) in switch circuits of thesecond array of tiles. An exposed region of conductive path 140-2 onfacing 150-1 provides a connectivity interface or common node couplingeach of the drain nodes in switch circuits of the first array and eachof the multiple drain nodes in switch circuits of the second array.

Thus, according to one embodiment herein, the row of drain nodes (D₁₁,D₁₂, and D₁₃) of the first array of circuits and the row of drain nodes(D₂₁, D₂₂, and D₂₃) of the second array of circuits are disposed to becloser in proximity to each other than a row of source nodes (S₁₁, S₁₂,and S₁₃) in the first array and a row of source nodes (S₂₁, S₂₂, andS₂₃) in the second array. Said differently, according to one embodiment,the row of drain nodes (D₁₁, D₁₂, and D₁₃) in the first array and therow of drain nodes (D₂₁, D₂₂, and D₂₃) in the second array are disposedor sandwiched between a row of source nodes (S₁₁, S₁₂, and S₁₃) of thefirst array and a row of source nodes (S₂₁, S₂₂, and S₂₃) of the secondarray.

Because the drain nodes in the two arrays face each other and can beconnected to a common node such as conductive path 140-2, fewerconductive paths are needed in the leadframe device 190. For example,according to one embodiment, reducing the number of conductive paths 140(e.g., one conductive path for to rows of drain nodes) in leadframedevice 190 can reduce an overall number of pins in the leadframe device190 that need to be attached to a circuit substrate, thus increasingcircuit reliability. Recall that a surface of the conductive pathbecomes a pad for connecting to a circuit board.

Of course, embodiments herein further include an electrical circuithaving any number of arrays of circuits in which the pattern andorientation of source nodes and drains nodes is alternated such thatrows of source nodes from one array of circuits to the next face eachother and rows of drain nodes from one array of circuits to the nextface each other.

Note that FIG. 2 further illustrates a connectivity interface couplingeach of the source nodes (S₁₁, S₁₂, and S₁₃) in circuits of the firstarray to the conductive strip or conductive path 140-1 and aconnectivity interface coupling each of the source nodes (S₂₁, S₂₂, andS₂₃) in switch circuits of the second array to the conductive strip orconductive path 140-4.

As previously discussed, each of the conductive paths or strips in theleadframe device 190 can be electrically isolated from each other. Forexample, the conductive path 140-1 can be electrically isolated fromconductive path 140-3. Conductive path 140-1 and conductive path 140-3can be electrically connected to each other via a trace on a hostcircuit board to which the leadframe device or circuit package ismounted.

FIG. 3 is a 3-D diagram illustrating another example how an electricalcircuit 120 is coupled to a leadframe device 190 according toembodiments herein. In this example figure, the conductive path 140-1has been removed for easier viewing of conductive path 140-2 andcorresponding contact element 345-2. In other words, conductive path140-2 is not occluded by conductive path 140-1 as in the previousfigure.

The contact element 345-1 (as in FIG. 2) and contact element 345-2 (inFIG. 3) can be offset with respect to each other so that respective padsunder the leadframe device 190 are space apart from each other as shownin FIG. 8. More details of the offset and pad configuration of facing150-2 are shown and discussed with respect to FIG. 8 below.

FIG. 4A is a diagram illustrating example functionality of the circuits210 residing on electrical circuit 120 according to embodiments herein.As shown, each circuit 210-1 can provide functionality such as a switchdevice.

In one embodiment, each circuit 210 includes a respective array of fieldeffect transistors in an integrated circuit that are connected inparallel to each other to form a switch circuit tile (e.g., circuit210). As previously discussed, the switch circuit tiles each cancomprise two electrical nodes (e.g., a source node and drain node) thatconnect to respective conductive paths 140 in the leadframe device 190.The common gates of circuit 210 are connected to and controlled bycontrol driver 410.

Electrical circuit 120 can include a control driver 410. In oneembodiment, as its name suggests, the control driver 410 produces a setof gate control signals that are used to drive the gates of eachrespective circuit 210.

In a further example embodiment, the gate control signals are formed inone or more metalization layer of a semiconductor device on which therespective switch tiles are formed. The electrical circuit 120 caninclude metalization to provide connectivity amongst the transistorswithin an array in the tile.

As shown in FIG. 4A and as previously discussed, the row of source nodesin a first array of circuits 210 can be disposed adjacent to or facing arow of source nodes in a second array of circuits 210 such that thesource nodes in the first array and source nodes in the second array canbe connected to a common conductive path in leadframe device 190. Therow of drain nodes in the second array of circuits 210 can be disposedadjacent to or facing a row of drain nodes in a third array of circuits210 such that the drain nodes in the second array and drain nodes in thethird array can be connected to another common conductive path inleadframe device 190.

FIG. 4B is an example diagram illustrating an example (silicon-based)wafer 495 having circuits 210 according to embodiments herein. Note thatinclusion of a control driver 410 is shown by way of non-limitingexample only. The electrical circuit 120 may or may not include circuit410 or other circuits.

Embodiments herein can include fabricating multiple circuits 210 on arespective wafer 495 such as that shown in FIG. 4B. The wafer 495 can becut (e.g., sliced and diced) depending on how many of the switchcircuits 210 are desired on a respective chip being packaged in theleadframe device 190. For example, the wafer 495 can be cut to producean electrical circuit 120-1 that has four circuits 210 (e.g., four tilesof parallel transistors). The wafer 495 can be cut to produce anelectrical circuit 120-2 that has nine circuits 210 (e.g., nine tiles ofparallel transistors). The wafer 495 can be cut to produce an electricalcircuit 120-3 that has twelve circuits 210 (e.g., twelve tiles ofparallel transistors). As previously discussed, portions or all of theelectrical nodes in each circuit can be independent of the nodes on theother circuits.

Of course, the leadframe device 190 can vary in size and shape as wellto accommodate the different sized circuits 120. In other words,different numbers of transistors can be connected in parallel to createa tile circuit.

The transistors in a tile circuit also can be of different sizes. Forapplications requiring more robust switching functionality, the packagealso can be adjusted in size to accommodate larger or smaller electricalcircuits 120. Conversely, for applications requiring less robustswitching functionality, the package can be larger to accommodate largerelectrical circuits 120.

As previously discussed, the leadframe device 190 is highly modular andscalable based on sizing and/or spacing of: conductive paths 140,circuits 210, circuit 120, source connections and drain connections oncircuits 210, etc.

In one embodiment, sizing of a circuit includes adding/deleting rowsand/or columns of a standard size of circuits 210 (e.g., a field effecttransistor array) to produce a family of devices having differentcapabilities.

FIG. 5 is an example diagram illustrating an electrical circuit 210-1according to embodiments herein. Note that each of multiple electricalcircuits 210 or tiles of circuit 120 can be configured in a similarmanner as circuit 210-1.

As shown, the example electrical circuit 210-1 can include arrays (e.g.,rows and columns) of transistors 520 such as multiple field effecttransistors in a semiconductor chip. The arrays of transistors 520 caninclude transistor 520-1, transistor 520-2, transistor 520-3, transistor520-4, transistor 520-5, transistor 520-6, transistor 520-7, transistor520-8, transistor 520-9, transistor 520-10, etc.

In one embodiment, an orientation of transistors in the integratedcircuit are alternated as shown such that drains in pairs of adjacentrows are close in proximity to each other; sources of transistors areclose to each other.

As mentioned above, the electrical circuit 210 can be one of multiplecircuits on a respective single integrated circuit substrate. Viametalization in the integrated circuit, the gate nodes, source nodes,and drain nodes of the transistors 520 can be connected to each other inparallel.

More specifically, based on connectivity such as metalization in anintegrated circuit, the source node of transistor 520-1 can be connectedto each of the source nodes of transistor 520-2, 520-3, 520-4, etc.; thesource node of transistor 520-2 can be connected to each of the sourcenodes of transistor 520-1, 520-3, 520-4, etc.; the source node oftransistor 520-3 can be connected to each of the source nodes oftransistor 520-1, 520-2, 520-4, etc.; and so on.

Via connectivity such as metalization in an integrated circuit, thedrain node of transistor 520-1 can be connected to each of the drainnodes of transistor 520-2, transistor 520-3, transistor 520-4, etc.; thedrain node of transistor 520-2 can be connected to each of the drainnodes of transistor 520-1, transistor 520-3, transistor 520-4, etc.; thedrain node of transistor 520-3 can be connected to each of the drainnodes of transistor 520-1, 520-2, 520-4, etc.; and so on. Thus, in oneembodiment, the array of transistors 520 can be interconnected to form asingle functional transistor circuit having a common source node (e.g.,node S₁₁) and common drain node (e.g., node D₁₁). In such an embodiment,the source node of each transistor 520 can be connected to common sourcenode S₁₁, the drain node of each transistor 520 can be connected tocommon drain node Dii. The common source node S₁₁ and the common drainnode D₁₁ couple to the conductive paths 140 in leadframe device 190.

Note that the gate node of each transistor 520 of circuit 210-1 can beelectrically coupled to a common point and be controlled by a commongate control signal. As mentioned, the gates can be connected with eachother via and interconnect such as metalization in an integratedcircuit.

FIG. 6 is an example diagram illustrating interconnectivity of tiles(e.g., circuits 210) in parallel via conductive paths 140 in theleadframe device 190 according to embodiments herein.

As shown, in a manner as previously discussed, circuit 210-1 effectivelybecomes a single, large transistor having its common source nodeconnected to conductive path 140-1 and common drain node connected toconductive path 140-2; circuit 210-2 is effectively a large transistorhaving its common source node connected to conductive path 140-1 andcommon drain node connected to conductive path 140-2; circuit 210-4 iseffectively a single, large transistor having its common drain nodeconnected to conductive path 140-2; and so on. Connecting the circuits210 has an effect of creating yet a larger transistor device.

As previously discussed, the metal layer of electrical circuit 120 caninclude gate control signals from control driver 410 to each of thecircuits 210. Creating paths for the gate control signals can besubstantially easier according to embodiments herein because theconductive paths 140 in the leadframe device 190 provide a level ofconnectivity amongst the circuits 210 in lieu of metalization in anintegrated circuit. Thus, control signals such as gate control signalsor other control signals can be laid out between tiles (e.g., circuits210) and thus not interfere with the interconnectivity layer disposedover the array of transistors in each circuit 210.

As shown, the spacing and/or widths of conductive paths can be selecteddepending on a spacing of the respective sources and drains of eachcircuit 210. For example, the spacing between conductive path 140-1 andconductive path 140-2 depends on locations of common source and drainnode connections on respective circuits 210-1, 210-2, 210-3, etc. Thus,if each circuit 210 is designed to include a larger sized array (e.g.,more rows and/or columns of transistors) or circuits 210, the spacing ofthe conductive paths 140-1 and conductive path 140-2 can be increased toaccount for a respective larger spacing between respective sources anddrains of circuits 210. Conversely, if the size and/or number oftransistors in the circuits 210 is reduced, the respective sourceconnections and drain connections of circuits 210 will be closertogether. In this latter case, a spacing and/or widths of conductivepaths 140-1 and 140-2 also can be adjusted or reduced to account for thechange in size of the circuits 210.

A spacing of the conductive paths 140 can be selected. In such a case,the size of circuits 210 and/or spacing of the sources and drainconnections on each circuit 210 can be adjusted to ensure that thesource and drain connections of each circuit 210 lines up with arespective conductive path 140 of leadframe device 190. Accordingly,embodiments herein include a highly scalable leadframe device 190.

As discussed herein, FIG. 6 illustrates that the conductive paths 140provide connectivity between the circuits 210 in lieu of having toprovide connectivity in one or more metalization layers of asemiconductor device. Use of the conductive paths 140 in a leadframedevice 190 provides unique current path interconnects between circuits210 (e.g., transistor array modules) to reserve a thick top layer metalin the circuit 120 such as a semiconductor device for routing of gatecontrol signals and/or other control signals between control driver 410and circuits 210. Accordingly, when circuit 120 is a semiconductordevice having multiple tiles or arrays of interconnected transistors,the conductive paths 140 provide a low impedance gate interconnectbetween tiles while a thick top metal layer of the semiconductor devicecan be used to provide connectivity between a centralized driver circuitand the multiple tiles. This simplifies a leadframe design and furtherenhances scalability.

FIG. 7 is an example diagram illustrating interconnectivity oftransistors 520 and hypothetical impedances according to embodimentsherein. As previously discussed, the transistors 520 can beinterconnected via metalization layers in an integrated circuit. By wayof a non-limiting example, the embodiment of FIG. 7 illustrates how themultiple transistors 520 of a tile can be interconnected in such a waythat the impedance paths for each transistor 520 are reasonably matchedwith each of the other transistors 520 in electrical circuit 210-1.

The impedance values A, B, C, D, E, F, G, H, I, J, K, L, M, etc.represent the impedances of conductive links (e.g., in metalizationlayers in an integrated circuit) between each of the transistors 520.The connectivity within the electrical circuit (and each of the otherelectrical circuits 210) can be configured such that the total impedancepath for any transistor is within a tolerance value such as within, forexample, 20%. In other words, the legs of the paths can be within anominal value +/−10 percent such that each transistor in a tile hasapproximately the same operating characteristics.

Assume in the present example model of circuit 210 that the impedancevalues A, B, C, D, E, F, G, H, I, J, K, L, M, etc. represent animpedance of approximately 12.5 milliohms each. Note that the value of12.5 milliohms is shown by way of non-limiting example only. The valuemay be different depending on the application.

The impedance associated with transistor 520-2 between node D₁₁ and nodeS₁₁ includes a sum of impedance D (approximately 12.5 milliohms),impedance B (approximately 12.5 milliohms), and impedance C(approximately 12.5 milliohms). Assume in this example that theimpedance between node D₁₁ and transistor 520-1 is negligible. Thus, thetotal impedance path for transistor 520-2 (not including the transistoritself) is approximately 45 milliohms.

In furtherance of this example, the impedance associated with transistor520-2 between node D₁₁ and node S₁₁ includes a sum of impedance D(approximately 12.5 milliohms), impedance B (approximately 12.5milliohms), and impedance C (approximately 12.5 milliohms). Thus, thetotal impedance path for transistor 520-2 (not including the transistoritself) is approximately 45 milliohms.

The impedance associated with transistor 520-3 between node Dii and nodeS₁₁includes a sum of impedance D (approximately 12.5 milliohms),impedance E (approximately 12.5 milliohms), and impedance C(approximately 12.5 milliohms). Thus, the total impedance path fortransistor 520-3 (not including the transistor itself) is approximately45 milliohms.

The impedance associated with transistor 520-4 between node D₁₁ and nodeS₁₁includes a sum of impedance D (approximately 12.5 milliohms),impedance E (approximately 12.5 milliohms), and impedance F(approximately 12.5 milliohms). Assuming that the impedance between nodeS₁₁ and transistor 520-4 is negligible, the total impedance path fortransistor 520-4 (not including the transistor itself) is approximately45 milliohms.

In a similar manner, the impedance path values for each of transistors520-5, 520-6, 520-7, 520-8, etc. are each approximately equal to 45milliohms as well.

Providing balanced path impedance interconnectivity in this manner isuseful because the burden of providing isolation/coupling is moreequally shared amongst the transistors 520. Thus, based on balancing inthe interconnect layer, no single one of group of transistors in acircuit 210 is unduly stressed under high current sinking or sourcingconditions.

FIG. 8 is an example diagram illustrating a view of facing 150-2 (e.g.,footprint and corresponding surface pads) of leadframe device 190 forconnecting the leadframe device 190 to a circuit board substrateaccording to embodiments herein.

According to this example embodiment, only portions of the conductivepaths 140 are exposed on a respective surface of the leadframe device190. For example, contact element 345-1 (rather than a whole length ofthe conductive path 140-1) is exposed on a bottom surface of theleadframe device 190 for attaching to a host such as printed circuitboard; contact element 345-2 (rather than a whole length of theconductive path 140-2) is exposed on a bottom surface of the leadframedevice 190 for attaching to a host such as printed circuit board; and soon. Forming the contact elements 345 to be less than the full length ofthe respective conductive path reduces a likelihood that the circuitelements 345 will be accidentally shorted to each other as there issubstantial spacing between contact element 345-2 and contact element345-2.

Forming a circuit package to have fewer pads or pins as discussed herein(based on orientation of the source s and drains to be near each other)renders it easier to mount the circuit package to a respective circuitboard substrate.

Note that additional pads 850 and corresponding conductive paths of theleadframe device 190 can provide connectivity with respect to theadditional circuitry of the electrical circuit 120. For example, thepads 850 of leadframe device 190 can provide conductive pathways from aprinted circuit board on which the leadframe device 190 resides and gatedriver or related circuitry of electrical circuit 120.

FIG. 9 is an example transparent view diagram illustratinginterconnectivity of electrical circuit 120 to corresponding traces of acircuit board via a leadframe device 190 according to embodimentsherein.

As shown, traces 950 can be electrically isolated from each other so asnot to short drains to sources, etc. Each of traces 950 can be a route,path, surface pad, conductive strip, etc., on a host such as a printedcircuit board to which the circuit 120 is mounted.

As previously discussed, each of circuits 210 in circuit 120 can beconfigured by interconnecting an array of field effect transistors inparallel to produce a respective field effect transistor switch circuit.Thus, as previously discussed, circuit 210-1 can be a first field effecttransistor switch circuit tile, circuit 210-2 can be a second fieldeffect transistor switch circuit tile, circuit 210-3 can be a thirdfield effect transistor switch circuit, circuit 210-4 can be a fourthfield effect transistor switch circuit tile, circuit 210-5 can be afifth field effect transistor switch circuit tile, circuit 210-6 can bea sixth field effect transistor switch circuit tile, circuit 210-7 canbe a seventh field effect transistor switch circuit, circuit 210-8 canbe an eighth field effect transistor switch circuit tile, and so on.

As shown, and as previously discussed, the circuits 210 of electricalcircuit 120 reside at a topmost level (e.g., connection interface 110-1)of the transparent view. At connection interface 110-1 (see also FIG.1), each circuit 210 connects to a corresponding conductive path 140beneath it.

For example, source node of circuit 210-1 connects to conductive path940-3; source node of circuit 210-2 connects to conductive path 940-3;source node of circuit 210-3 connects to conductive path 940-3; and soon. Drain node of circuit 210-1 connects to conductive path 940-4; drainnode of circuit 210-2 connects to conductive path 940-4; drain node ofcircuit 210-3 connects to conductive path 940-4; and so on. Aspreviously discussed, the source nodes and drain nodes of eachrespective circuit can be electrically isolated from each other exceptfor respective electrical connections provided by the conductive paths140.

As shown, source node of circuit 210-5 connects to conductive path940-3; source node of circuit 210-6 connects to conductive path 940-3;source node of circuit 210-7 connects to conductive path 940-3; and soon. Drain node of circuit 210-5 connects to conductive path 940-2; drainnode of circuit 210-6 connects to conductive path 940-2; drain node ofcircuit 210-7 connects to conductive path 940-2; and so on.

As shown, source node of circuit 210-9 connects to conductive path940-2; source node of circuit 210-10 connects to conductive path 940-2;source node of circuit 210-11 connects to conductive path 940-2; sourcenode of circuit 210-12 connects to conductive path 940-2; and so on.Drain node of circuit 210-9 connects to conductive path 940-1; drainnode of circuit 210-10 connects to conductive path 940-1; drain node ofcircuit 210-11 connects to conductive path 940-1; drain node of circuit210-12 connects to conductive path 940-1; and so on.

In contrast to the embodiments as discussed above, coupling of bothsource nodes and drain nodes to conductive path 940-2 creates a seriesconnection of the high side switch 1242 and the low side switch 1246 asin FIG. 10. High side switch 1242 as implemented in the circuit packageof FIG. 9 includes a parallel combination of circuits 210-9, 210-10,210-11, and 210-12. Low side switch 1246 as implemented in the circuitpackage of FIG. 9 includes a parallel combination of circuits 210-1,210-2, 210-3, 210-4, 210-5, 210-6, 210-7, 210-8, and so on. Trace 950-1connects to Vcc, trace 950-2 connects to ground, trace 950-3 connects toswitch node of inductor 1244.

Referring again to FIG. 9, connection interface 110-2 providesconnectivity between the contact elements (cross-hatched regions ofrespective conductive paths 140) of leadframe device 190 and the circuitboard or substrate on which traces 950 reside. For example, thecross-hatched section (e.g., pad or pin) of conductive path 940-1connects the conductive path 940-1 to trace 950-1 of the circuit board;the cross-hatched section (e.g., pad or pin) of conductive path 940-2connects the conductive path 940-2 to trace 950-3 of the circuit board;the cross-hatched section (e.g., pad or pin) of conductive path 940-3connects the conductive path 940-3 to trace 950-2 of the circuit board;the cross-hatched section (e.g., pad or pin) of conductive path 940-4connects the conductive path 940-4 to trace 950-3 of the circuit board;and so on.

Accordingly, via conductive paths 940, the source nodes and drain nodesget connected to respective traces 950.

As mentioned, each of the conductive paths 940-2 and 940-4 can beelectrically isolated from each other until after the leadframe device190 is connected to a host substrate. After forming a physicalconnection between the leadframe device 190 and host as discussed above,the conductive paths 940-2 and 940-4 become electrically connected viatrace 950-1.

Via application of a gate signal to appropriate circuits 210, the switchcircuits 210 provide a low impedance path or high impedance path betweentrace 950-1 and trace 950-3 or between trace 950-2 and trace 950-3. Morespecifically, an OFF gate signal applied to circuits in the high sideswitch 1242 (e.g., a combination of circuits 210-9, 210-10, 210-11, and210-12) causes the circuits 210 to provide a high impedance path betweenVcc and the switch node. An ON gate signal applied to circuits in thehigh side switch 1242 causes the combination of circuits to provide alow impedance path.

An OFF gate signal applied to circuits in the low side switch 1246(e.g., a combination of circuits 210-1, 210-2, 210-3, . . . , and 210-8,. . . ) as shown causes the circuits 210 in the low side switch 1246 toprovide a high impedance path between the switch node and ground. An ONgate signal applied to circuits in the low side switch 1246 causes thecircuits in the low side switch 1246 to provide a low impedance pathbetween the switch node and ground.

Control signals for driving switch can be generated interally withrespect to the electrical circuit 120 or received off-chip via signalson the host substrate that are passed up to the electrical circuit 120via conductive paths in the leadframe device 190. In one embodiment, adriver circuit 410 disposed on electrical circuit 120, when soconfigured, generates the switch control signals based on receipt of aninput signal. The input signal can be received by the driver circuit 410from the circuit board substrate via one or more conductive path in theleadframe device 190 between the host substrate and the driver circuit.

Thus, embodiments herein further include a packaged circuit devicecomprising: a conductive strip 940-2 and a semiconductor chip substrate995 including a first array of switch circuits (e.g., switch circuit210-9, switch circuit 210-10, switch circuit 210-11, switch circuit210-12, . . . ) disposed substantially adjacent and substantiallyparallel to a second array of switch circuits (e.g., switch circuit210-5, switch circuit 210-6, switch circuit 210-7, switch circuit 210-8,. . . ). A first connectivity interface of the conductive strip 940-2couples switch circuits 210 in the first array and switch circuits 210in the second array to the conductive strip 940-2. A second connectivityinterface of the conductive strip 940-2 can be configured toelectrically couple the conductive strip 940-2 in the packaged circuitto one or more electrical nodes of a host circuit substrate to which thepackaged circuit device can be attached or mounted.

Any suitable method can be used to couple the nodes of circuits 210 tothe conductive strips. By way of a non-limiting example, one way tocouple nodes such as source nodes and drain nodes of the circuits 210 tothe conductive strips is solder.

As previously discussed, each switch circuit 210 in the first array ofswitch circuits 210-9, 210-10, 210-11, and 210-12 can include arespective set of transistors connected in parallel with each other viaconnectivity provided in the semiconductor chip substrate. Each switchcircuit in the second array of switch circuits 210-5, 210-6, 210-7,210-8 can include a respective set of transistors connected in parallelwith each other via connectivity provided in the semiconductor chipsubstrate. Each switch circuit in the third array of switch circuits210-1, 210-2, 210-3, 210-4 can include a respective set of transistorsconnected in parallel with each other via connectivity provided in thesemiconductor chip substrate.

Switch circuits in the first array and switch circuits in the secondarray can be electrically isolated from each other except for thecircuit connectivity provided by the conductive strip 940-2 between thenodes of the first array of switch circuits and nodes of the secondarray of switch circuits.

In one embodiment, each switch circuit in the first array of switchcircuits includes a source node and a drain node; each switch circuit inthe second array of switch circuits includes a source node and a drainnode. The connectivity interface provides electrical coupling of sourcenodes in the first array of switch circuits to drain nodes in the secondarray of switch circuits.

In further embodiments, the source nodes of switch circuits in the firstarray form a first array of circuit nodes; the drain nodes in the secondarray form a second array of circuit nodes. As shown, the first array ofcircuit nodes can be disposed substantially parallel to the second arrayof circuit nodes.

In addition to the first array and second array of switch circuits asdiscussed above, circuit substrate (such as a semiconductor chipsubstrate) can include a third array of switch circuits (e.g., switchcircuit 210-1, 210-2, 210-3, 210-4, . . . ) disposed substantiallyadjacent and substantially parallel to the first and second array ofswitch circuits. Another connectivity interface in the packaged circuitdevice couples switch circuits 210 in the third array and switchcircuits in the second array to the conductive strip 940-3. For example,in one embodiment, the conductive strip 940-3 electrically couplessource nodes in the second array of switch circuits to source nodes inthe third array of switch circuits 210-1, 210-2, 210-3, and 210-4.Embodiments herein can include packaging equipment or manufacturingequipment to manufacture leadframe devices.

Such equipment can be configured to: receive a semiconductor chipsubstrate 995 including a first array of switch circuits 210 disposedsubstantially adjacent and substantially parallel to a second array ofswitch circuits; and receive a leadframe package 190 including aconductive strip 940-2. The conductive strip 940-2 can include aconnectivity interface to electrically couple the conductive strip 940-2in the leadframe package 190 to an electrical node of a host circuitsubstrate 170. The packaging equipment can provide or create aconnectivity interface coupling switch circuits 210 in the first arrayand switch circuits in the second array to the conductive strip 940-2 ofthe leadframe package 190. Thus, circuit substrate can be attachedand/or coupled to one or more conductive strips in the leadframe package190.

In one embodiment, the switch circuits in the first array and switchcircuits in the second array are electrically isolated from each otherexcept for circuit connectivity (e.g., a highly conduit path) providedby the conductive strip between the first array of switch circuits andthe second array of switch circuits. In other words, the one or moreconductive strips in the leadframe package can connect the circuits 210in parallel with each other. Additionally, a conductive strip canprovide serial connectivity. For example, conductive strip 940-2serially connects the first array of switch circuits 210 (e.g., highside switch) and second array of switch circuits 210 (e.g., low sideswitch) with each other.

In further embodiments, the manufacturing equipment providing theconnectivity interface couples source nodes in the first array of switchcircuits 210-9, 210-10, 210-11, and 210-12 to drain nodes in the secondarray of switch circuits 210-5, 210-6, 210-7, and 210-8 via theconductive strip 940-2. The first array of switch circuits (e.g.,forming a high side switch 1242) and second array of switch circuits(e.g., forming a low side switch 1246) are serially connected with eachother via the conductive strip 940-2.

Embodiments herein can further include manufacturing equipmentconfigured to electrically coupling switch circuits in the third array(e.g., circuit 210-1, 210-2, 210-3, and 210-4) and switch circuits inthe second array to conductive strip 940-3 of the leadframe package 190.The conductive strip 940-3 can be substantially adjacent andsubstantially parallel to conductive strip 940-2 as shown. In oneembodiment, the leadframe packaging equipment electrically couplessource nodes in the second array of switch circuits 210-5, 210-6, 210-7,210-8 to source nodes in the third array of switch circuits via theconductive strip 940-3.

FIG. 10 is a diagram illustrating functionality associated with anexample leadframe device 190 of a power supply system 1200 according toembodiments herein.

More specifically, a leadframe device 190 populated according toembodiments herein can be configured to include a phase controller 1240(e.g., controller logic), a control driver 410 (e.g., control driver410-1 and control driver 410-2), high side switch 1242, low side switch1246, as well as any other conventional circuitry to control an outputvoltage applied to power load 118. As discussed above, a parallelconnection of switch circuits 210-9, 210-10, 210-11, and 210-12 can forma high side switch 1242 of a switching power supply. Note that anynumber of switch circuits 210 can be connected in parallel to form ahigh side switch. A parallel connection of switch circuits 210-1, 210-2,210-3, 210-4, 210-5, 210-6, 210-7, 210-8, etc. as shown can form a highside switch 1242. Note that any number of switch circuits 210 can beconnected in parallel to form a low side switch of a switching powersupply.

According to other embodiments, note that the phase controller residesin a circuit separate from the high side switch and low side switch. Insuch an embodiment, leadframe device 190 or circuit package as discussedherein can include merely the high side switch 1242 and low side switch1246 as discussed with respect to FIG. 9 above.

Referring again to FIG. 10, phase controller 1240 monitors the outputvoltage 1280 and generates appropriate control signals for driving highside switch circuitry 1242 and low side switch circuitry 1246 in theleadframe device 190. The high side switch circuitry 1242 and low sideswitch circuitry 1246 of power supply system 1200 represent thefunctionality provided by connection of circuits 210 (on circuit 120)via conductive paths 140 to a host such as a printed circuit board asdescribed herein.

As previously discussed, additional conductive paths in the leadframedevice 190 can provide connectivity between circuit 120 and a respectiveprinted circuit board. Accordingly, any portion or functionality of apower supply system 1200 can reside in leadframe device 190 rather thanon the printed circuit board.

A benefit of such a configuration is space savings. Typically,conventional power supplies require layout of many components on arespective printed circuit board to create a power supply. This requiresconsiderable printed circuit board real estate and cost to assemble. Incontrast to conventional techniques, inclusion of control circuitryand/or related circuitry on leadframe device 190 as described herein canreduce an overall impact of populating a printed circuit board with apower supply control system because a printed circuit board can bepopulated with one or more leadframe devices rather than a multitude ofindividual components. Further enhancements over conventional techniquesas discussed herein reduce a number of pads associated with theleadframe device 190.

Again, each of the high side switch circuitry 1242 and low side switchcircuitry 1246 of leadframe device 190 can be configured in accordancewith the techniques as discussed herein.

More specifically, in an example embodiment, a first set of conductivepaths 140 in the leadframe device 190 can provide parallel connectivityamongst multiple circuits 210 of circuit 120 to produce high side switchcircuitry 1242; a second set of conductive paths 140 in the leadframedevice 190 can provide parallel connectivity amongst multiple circuits210 in circuit 120 to produce low side switch circuitry 1246; and so on.As previously discussed, the leadframe device 190 includes contactelements 145 for connecting the switch circuitry to a printed circuitboard.

Each phase in power supply system 1200 can require a respectiveindependently operating high side switch and low side switch. Theleadframe device 190 can be configured to provide switching circuitryfor each of a number of phases. Thus, in certain embodiments, theleadframe device 190 can include a multi-phase power supply controllerand related circuitry.

In addition to including control driver 410 as discussed above in FIG.4A, note that circuit 120 can include phase controller 1240 formonitoring output voltage 1280 and producing phase control signals tocontrol respective high side switch circuitry 1242 and low side switchcircuitry 1246 for the embodiment as discussed in FIG. 10. Accordingly,the leadframe device 190 can include any suitable circuits to facilitategeneration of output voltage 180.

Additionally, note that the leadframe device 190 can be configured toinclude a conductive path from circuit 120 to communication link 1291 ona printed circuit board such that the phase controller 1240 andprocessor 1292 (also on circuit board) can communicate with each other.In one embodiment, the output voltage 180 can be used to power theprocessor 1292.

As shown in the example embodiment of FIG. 10, during operation, phasecontroller 1240 generates control signal 1241-1 to control respectivehigh side switch circuitry 1242 and control signal 1241-2 to control lowside switch circuitry 1246. When high side switch circuitry 1242 isturned ON via controller 1240 (while low side switch circuitry 1246 isOFF), the current through inductor 1244 increases via a conductive pathprovided by high side switch circuitry 1242 between voltage source 1230and inductor 1244. When low side switch circuitry 1246 is turned ON viacontroller 1240 (while high side switch circuitry 1242 is OFF), thecurrent through inductor 1244 decreases based on a conductive paththrough the low side switch circuitry 1246 between the inductor 1244 andground.

As mentioned above, based on switching of the high side switch circuitry1242 and the low side switch circuitry 1246, the leadframe device 190(e.g., a power supply control system) can regulate the output voltage1280 within a desired range for providing power to load 118.

In one embodiment, leadframe device 190 can include respective circuitryto control any number of phases present in leadframe device 190 of apower supply system 1200. Each phase can include high side switchcircuitry and low side switch circuitry as previously discussed. Todeactivate a respective phase, the phase controller 1240 can set bothhigh side switch circuitry 1242 and low side switch circuitry 1246 ofthe phase to an OFF state.

Respective high and low side switches for each of multiple phases can bedisposed in a single leadframe device 190. Alternatively, high and lowside switches for a respective phase can be disposed in a single circuitpackage. In this latter embodiment, a circuit package is needed for eachphase to perform switching operations.

FIG. 11 is a diagram illustrating an example leadframe device 190according to embodiments herein. As shown, conductive paths 140 inleadframe device 190 provide connectivity amongst a number of transistorarrays (e.g., multiple rows of transistors connected in parallel asdiscussed above) to provide high and low side switching capability foreach of one or more phases supported by the leadframe device 190.

As previously discussed, the leadframe device 190 according toembodiments herein can provide connectivity with traces on a hostcircuit board via conductive paths through the leadframe device 190.

In this example configuration of FIG. 11, conductive path 1320-1,conductive path 140-1, conductive path 140-2, conductive path 140-3,etc., provide connectivity from the circuits 210 through the leadframedevice 190 to a respective circuit such as a host on which the leadframedevice 190 resides. Accordingly, via such connectivity, any componentspreviously mounted to a host circuit board can be located on theleadframe device 190 instead.

As mentioned above, different families of leadframe devices or sizes ofleadframe devices can be manufactured using different numbers ofcircuits 210 (e.g., switch tiles 210). For example, a number of circuitsincluded in a leadframe device 190 can vary by adding or removing rowsand/or columns of tiles of an integrated circuit that is subsequentlypackaged in a leadframe device.

In accordance with a first specification, embodiments herein include:receiving a first integrated circuit, the first integrated circuithaving a first set of electrically isolated switch circuit nodesdisposed thereon; receiving a first leadframe device in which to packagethe first integrated circuit; and electrically coupling the firstintegrated circuit to a facing of the first leadframe device to provideconnectivity between the first set of electrically isolated switchcircuit nodes on the first integrated circuit via at least oneconductive path in the first leadframe device. The electrically isolatedswitch circuit nodes can include a row of source nodes in a first arrayof transistors disposed adjacent to a row of source nodes in a secondarray of transistors as discussed herein.

In accordance with a second specification that is modified or differentwith respect to the first specification, embodiments herein include:receiving a second integrated circuit, the second integrated circuithaving a second set of electrically isolated switch circuit nodesdisposed thereon, the second integrated circuit having a differentnumber of electrically isolated switch circuit nodes than the firstintegrated circuit; receiving a second leadframe device in which topackage the second integrated circuit; and electrically coupling thesecond integrated circuit to a facing of the second leadframe device toprovide connectivity between the second set of electrically isolatedswitch circuit nodes via at least one conductive path in the secondleadframe device. The electrically isolated switch circuit nodes caninclude a row of source nodes in a first array of transistors disposedadjacent to a row of source nodes in a second array of transistors asdiscussed herein.

Thus, a number of switch tiles can be added or removed from one designto another to create circuit package devices having different switchingcapabilities.

FIG. 12 is a flowchart 1200 illustrating an example method of packagingan electrical circuit 120 in a leadframe device 190 according toembodiments herein. Note that there will be some overlap with respect toconcepts as discussed above. In one embodiment, the steps in FIG. 12 areperformed by one or more manufacturing facilities, machines, handlers,etc., that produce circuit packages.

Step 1210 includes receiving a leadframe component including a firstconductive strip, a second conductive strip, and a third conductivestrip disposed substantially adjacent and substantially parallel to eachother. Each of the conductive strips can be a conductive path 140 in aleadframe device 190.

Step 1220 includes receiving a semiconductor chip substrate such ascircuit 120 including a first array of switch circuits 210 or tilesdisposed adjacent and parallel to a second array of switch circuits 210.Each of the switch circuits 210 can include a primary node (e.g., firsttype of node) such as a source node and secondary node (e.g., secondtype of node) such as a drain node. Primary nodes in switch circuits ofthe first array are disposed substantially adjacent (e.g., next to) andsubstantially parallel to primary nodes in switch circuits of the secondarray.

Step 1230 includes electrically coupling each of the primary nodes inswitch circuits 210 of the first array and each of the primary nodes inswitch circuits 210 of the second array to a single conductive stripsuch as the second conductive strip in the leadframe device 190.Accordingly, rows of primary nodes in adjacent arrays of transistors canbe connected to a single conductive strip as opposed to two separateconductive strips in a circuit package as is done in conventionalmethods.

FIG. 13 is a flowchart 1300 illustrating a detailed example method ofpackaging an electrical circuit 120 in a leadframe device 190 accordingto embodiments herein. Note that there will be some overlap with respectto concepts as discussed above. In one embodiment, the steps in FIG. 13are performed by one or more manufacturing facilities, machines,handlers, etc., that produce circuit packages.

Step 1310 includes receiving a leadframe component comprising a firstconductive strip, a second conductive strip, and a third conductivestrip disposed substantially adjacent and substantially parallel to eachother. As mentioned, each of the conductive strips can be a conductivepath 140 in a leadframe device 190.

Step 1320 includes receiving a circuit 120 such as a semiconductor chipsubstrate. The semiconductor chip substrate can include a first array ofswitch circuits 210 (e.g., tiles) disposed adjacent and parallel to asecond array of switch circuits 210 (e.g., tiles). By way of anon-limiting example, source nodes in switch circuits of the first arrayare disposed adjacent (e.g., next to) and substantially parallel tosource nodes in switch circuits of the second array. In one embodiment,the row of source nodes in the first array and the row of source nodesin the second array are disposed on the semiconductor chip substratebetween a row of drain nodes of the first array and a row of drain nodesof the second array.

Step 1330 includes aligning the source nodes of the first circuit arrayand the source nodes of the second circuit array over a singleconductive path such as the second conductive strip.

Step 1340 includes electrically coupling each of the source nodes inswitch circuits of the first array and each of the source nodes inswitch circuits of the second array to the second conductive strip.

Step 1350 includes electrically coupling each of the drain nodes inswitch circuits 210 of the first array to the first conductive strip.

Step 1360 includes electrically coupling each of the drain nodes inswitch circuits of the second array to the third conductive strip.

Step 1370 includes mounting a leadframe package or device including thefirst conductive strip, second conductive strip, and third conductivestrip to a host circuit board to electrically couple the firstconductive strip and the third conductive strip to each other. In oneembodiment, the second conductive strip is electrically isolated fromthe first conductive strip and the third conductive strip.

FIG. 14 is a flowchart 1400 illustrating an example method of creatingan electrical circuit 120 according to embodiments herein. Note thatthere will be some overlap with respect to concepts as discussed above.In one embodiment, the steps in FIG. 14 are performed by one or moremanufacturing facilities, machines, handlers, etc., that producecircuits 120.

Step 1410 includes disposing a first array of switch circuits on acircuit 120 such as a semiconductor chip substrate.

Step 1420 includes disposing a second array of switch circuits on thesemiconductor chip substrate. Each switch circuit in the first array andthe second array can be of a substantially same type and include aprimary node (e.g., a source node) and a secondary node (e.g., asecondary node).

Step 1430 includes disposing primary nodes in switch circuits of thefirst array on the semiconductor chip substrate to be adjacent toprimary nodes in switch circuits of the second array.

FIG. 15 is a flowchart 1500 illustrating an example method of creatingan electrical circuit 120 according to embodiments herein. Note thatthere will be some overlap with respect to concepts as discussed above.In one embodiment, the steps in

FIG. 15 are performed by one or more manufacturing facilities, machines,handlers, etc., that produce circuits.

Step 1510 includes disposing a first array of switch circuits 210 on acircuit such as a semiconductor chip substrate. Each switch circuit 210in the first array includes a primary node such as a source node and asecondary node such as a drain node. Each switch circuit 210 in thefirst array comprises a respective set of transistors connected inparallel with each other via an interconnect layer associated with thesemiconductor chip substrate.

Step 1520 includes disposing a second array of switch circuits 210 onthe semiconductor chip substrate. Each switch circuit 210 in the secondarray includes a source node and a drain node. Each switch circuit inthe second array comprises a respective set of transistors connected inparallel with each other via the interconnect layer.

Step 1530 includes disposing source nodes in switch circuits of thefirst array on the semiconductor chip substrate to be adjacent to sourcenodes in switch circuits of the second array. Sub-step 1540 includesdisposing the source nodes of the first array and the source nodes ofthe second array on the semiconductor chip substrate to be between a rowof drain nodes of the first array and a row of drain nodes of the secondarray.

Step 1550 includes producing each switch circuit 210 in the first arrayto be electrically isolated from each other prior to coupling of theswitch circuits 210 in the semiconductor chip substrate to conductivepaths 140 in a leadframe device 190.

Step 1560 includes producing each switch circuit 210 in the second arrayto be electrically isolated from each other prior to coupling of switchcircuits 210 in the semiconductor chip substrate to the leadframe device190.

FIG. 16 is an example diagram illustrating layering and fabrication of acircuit 210 according to embodiments herein. Note that the thickness ofeach layer with respect to others is not necessarily drawn to scale.

As previously discussed, circuit 210 can be an integrated circuitdevice. In this example embodiment, circuit 210 includes a transistorlayer 1610 (e.g., a semiconductor layer). Such a layer can includehundreds, thousands, millions, . . . of individual transistors such asfield effect transistors, bipolar junction transistors, etc.

According to one embodiment, one or more interconnect layers 1620 (e.g.,so-called metalization layers) in circuit 210 connect the transistors inparallel.

Transistors in the transistor layer 1610 can be electrically connectedto conductive layer 1630 via interconnect layer 1620. Conductive layer1630 can be electrically divided into different portions. For example, afirst portion of conductive layer 1630 (e.g., conductive source nodelayer 1630-1) can be a first common circuit node of the multipletransistors connected in parallel with each other; a second portion ofthe conductive layer 1630 (e.g., conductive drain node layer 1630-2) canbe a second common circuit node of the multiple transistors connected inparallel with each other.

In one embodiment, a source node of each transistor in the transistorlayer 1610 is electrically coupled to conductive source node layer1630-1 via the interconnect layer 1620. A drain node of each transistorin the transistor layer 1610 is electrically coupled to conductive drainnode layer 1630-2 via the interconnect layer 1620. Although they residein the same layer, the conductive source node layer 1630-1 iselectrically isolated from the conductive drain node layer 1630-2.

As will be discussed later in this specification, a set of transistorsin the transistor layer 1610 resides beneath the conductive source nodelayer 1630-1. Another set of transistors in the transistor layer 1610resides beneath the conductive drain node layer 1630-2.

For a transistor residing beneath a region of the conductive source nodelayer 1630-1, a relatively short circuit path (e.g., a substantiallyvertical path) in the interconnect layer 1620 can connect the sourcenode of the respective transistor to the conductive source node layer1630-1. A longer circuit path in the interconnect layer 1620 is neededto connect the drain node of the respective transistor to the conductivedrain node layer 1630-2 because such a circuit path must traversehorizontally in the interconnect layer 1620 from the respectivetransistor and up to the conductive drain node layer 1630-2.

For a transistor residing beneath a region of the conductive drain nodelayer 1630-2, a relatively short circuit path (e.g., a substantiallyvertical path) in the interconnect layer 1620 can connect the drain nodeof the respective transistor to the conductive drain node layer 1630-2.A longer circuit path is needed to connect the source node of therespective transistor to the conductive source node layer 1630-1 becausesuch a circuit path must traverse horizontally in the interconnect layer1620 from the respective transistor and up to the conductive source nodelayer 1630-1.

Dielectric layer 1640 such as a non-conductive material resides overconductive layer 1630. Dielectric layer 1640 can include a field ofconductive interconnect links (e.g., conductive elements such as pillar126-1, pillar 126-2, pillar 126-3, pillar 126-4, . . . , pillar 126-25,pillar 126-26, . . . ). Each link extends through the dielectric layer1640 to connect conductive layer 1630 to conductive layer 1650. By wayof a non-limiting example, successive pillars 126 can be spaced apartfrom each other by 60 micrometers in a grid like manner. Each pillar 126can be of a diameter as 20 micrometers. However, note that thesedimensions can vary depending on the application.

More specifically, a first set of pillars 126 or contact elements indielectric layer 1640 electrically connect conductive source node layer1630-1 to conductive source node layer 1650-1. A second set of pillars126 or contact elements in dielectric layer 1640 electrically connectconductive drain node layer 1630-1 to conductive drain node layer1650-1. Accordingly, via the first set of links in the dielectric layer1640, the conductive source node layer 1630-1 is electrically connectedto the conductive source node layer 1650-1. Via the second set ofpillars in the dielectric layer 1640, the conductive drain node layer1630-2 is electrically connected to the conductive drain node layer1650-2.

In one embodiment, the pillars 162 are links made from a metal such ascopper to provide connectivity between conductive layer 1630 andconductive layer 1650.

By way of a non-limiting example, conductive layer 1630 can befabricated from a conductive material such as a first type of metal.Conductive layer 1650 can be fabricated from a second type of metal.

In a specific embodiment, the conductive layer 1630 is made fromaluminum and the conductive layer 1650 is made from copper. Copper has alower resistivity than aluminum. Said differently, copper is a betterconductor of electricity than aluminum. In general, fabricatingconductive layer 1650 with a conductive material having a relativelylower resistivity (than a resistivity of conductive layer 1630) reducesan overall thickness of the circuit 210. For example, by way of anon-limiting example, the conductive layer 1630 can be formed from(approximately) a 3-micrometer layer of aluminum. Conductive layer 1650can be formed from (approximately) a 6-micrometer layer of aluminum aswell. However, forming conductive layer 1650 based on copper (instead ofaluminum) can reduce an overall thickness of the circuit 210. That is,because copper has a higher conductivity (e.g., lower resistivity) thanaluminum, forming conductive layer 1650 based on a material such ascopper (e.g., 3 micrometers) can reduce an overall thickness of circuit210 without negatively impacting characteristics of the device. In otherwords, a 3 micrometer layer of copper in layer 1650 can provide arelatively comparable low resistive path as would a 6 micrometer layerof aluminum. Thus, according to one embodiment, utilizing 3 micrometersof copper instead of a 6 micrometer thickness of aluminum reduces athickness of the circuit by 3 micrometers.

Layer 1660 includes source node 1680-1 and drain node 1680-2 providingconnectivity between the conductive source node layer 1650 andrespective conductive path 140 in leadframe device 190.

By way of a non-limiting example, in one embodiment, the source node1680-1 and drain node 1680-2 can be 100 micrometers tall and have adiameter of approximately 85 micrometers. However, note that the sourcenode 1680-1 and drain node 1680-2 of circuit 210 can vary depending onthe application.

FIG. 17 is an example diagram illustrating a top view of a fabricatedcircuit 210 (e.g., tile region associated with circuit 120) according toembodiments herein. By way of a non-limiting example, the circuit 210can be 500 micrometers wide and 1000 micrometers long. However, circuit210 can be any suitable dimensions.

As shown, circuit 210 includes conductive layer 1630 disposed overinterconnect layer 1620. Interconnect layer 1620 connects nodesassociated with transistors in transistor layer 1610 to the conductivelayer 1630. For example, as previously discussed, the interconnect layer1620 connects a source node of each transistor in the transistor layer1610 to conductive source node layer 1630-1. The interconnect layer 1620connects a drain node of each transistor in the transistor layer 1610 toconductive drain node layer 1630-2.

In one embodiment, the conductive layer 1630 is partitioned as shownsuch that each transistor connected in parallel has similar operatingcharacteristics.

As discussed above with respect to FIG. 7, the multiple transistors incircuit 210 (or tile) can be interconnected in such a way that theimpedance of interconnect paths for each transistor are reasonablymatched with each of the other transistors in electrical circuit 210-1.In other words, for any given transistor residing in the transistorlayer 1610, a source of the transistor can be connected to theconductive source node layer 1630-1 and the drain can be connected tothe conductive drain node layer 1630-2 such that the total resistance orimpedance of an interconnect path including a first interconnect legfrom a source node of the given transistor to the conductive source nodelayer 1630-1 plus a second interconnect leg from a drain node of thegiven transistor to the conductive drain is within a tolerance such as20% with respect to the same measured impedance of other transistors.Thus, by way of a non-limiting example, the resistance of legs of theinterconnect paths can be within a nominal value +/−10 percent such thateach transistor in a tile has approximately the same operatingcharacteristics.

Providing balanced path impedance interconnectivity in this manner isuseful because the burden of providing isolation/coupling is moreequally shared amongst the transistors 520. Thus, no single one or groupof transistors in the transistor layer 1620 is unduly stressed as aresult of high current sinking or sourcing conditions.

FIG. 18 is an example diagram illustrating a top view of the field ofconductive elements 126 disposed in layer 1640 according to embodimentsherein. As previously discussed, the field of conductive elements 126 inthe source region provides connectivity between conductive source nodelayer 1630-1 and conductive source node layer 1650-1. The field ofconductive elements 126 in the drain region provides connectivitybetween conductive drain node layer 1630-2 and conductive source nodelayer 1650-2.

FIG. 19 is an example diagram illustrating a top view of conductivelayer 1650 according to embodiments herein. As previously discussed, theconductive source node layer 1650-1 is electrically isolated fromconductive drain node layer 1650-2. That is, a first portion of theconductive layer 1650 represents a source node of multiple transistorsin parallel; a second portion of the conductive layer 1650 represents adrain node of multiple transistors in parallel.

FIG. 20 is an example diagram illustrating a top view of layer 1660according to embodiments herein.

As shown, the dielectric layer 1660 can be an electricallynon-conductive material. Source node 1680-1 extends through theconductive layer 1660 to conductive source node layer 1650-1. Drain node1680-2 extends through the conductive layer 1660 to conductive drainnode layer 1650-2.

In one embodiment, the source node 1680-1 and drain node 1680-2 areconductive pillars made from copper. However, the source node 1680-1 anddrain node 1680-2 can be any suitable type of electrically conductivematerial or shape such as a solder ball. By way of a non-limitingexample, in one embodiment, the source node 1680-1 and drain node 1680-2can be space approximately 550 micrometers apart from each other.However, note that this dimension can vary depending on the application.

As previously discussed, the source node 1680-1 can be electricallycoupled to a respective conductive path 140 or conductive strip in theleadframe device 190. In such an embodiment, each of the transistors inthe transistor layer 1610 can be electrically connected to a respectiveconductive path 140 in the leadframe device 190 via a series ofconnectivity paths through a combination of the interconnect layer 1620,the conductive source node layer 1650-1, the field of conductive fieldelements 126 in the source region, the conductive source node layer1650-1, and the source node 1680-1.

As previously discussed, the source node 1680-2 can be electricallycoupled to a respective conductive path 140 in the leadframe device 190.In such an embodiment, transistors in the transistor layer 1610 can beelectrically connected to a respective conductive path 140 or conductivestrip in the leadframe device 190 via a series of connectivity pathsthrough a combination of the interconnect layer 1620, conductive drainnode layer 1650-2, field of conductive field elements 126 in the drainregion, conductive drain node layer 1650-2, and drain node 1680-2.

FIG. 21 is a flowchart 2200 illustrating an example method of creatingcircuit 210 via different layers according to embodiments herein. Notethat there will be some overlap with respect to concepts as discussedabove. In one embodiment, the steps in FIG. 22 are performed by one ormore manufacturing facilities, machines, handlers, etc., that producecircuits 120 and/or circuits 210.

Step 2210 includes producing a transistor layer 1610 (e.g.,semiconductor layer, circuit layer, etc.) to include multipletransistors.

Step 2220 includes fabricating one or more interconnect layers 1620 onthe transistor to connect the multiple transistors in parallel with eachother.

Step 2230 includes fabricating a conductive layer 1630 on the one ormore interconnect layers 1620. The one or more interconnect layer 1620electrically couples multiple transistors in the transistor layer to theconductive layer 1630. The conductive layer 1620 can be a first type ofmaterial having a first resistivity.

Step 2240 includes electrically coupling conductive layer 1650 toconductive layer 1650. The conductive layer 1650 can be a second type ofmaterial having a second resistivity. In one embodiment, the secondresistivity is less than the first resistivity.

FIGS. 22 and 23 combine to form a flowchart 2300 (e.g., flowchart 2300-1and 2300-2) illustrating an example method of creating circuit 210according to embodiments herein. Note that there will be some overlapwith respect to concepts as discussed above. In one embodiment, thesteps in flowchart 2300 are performed by one or more manufacturingfacilities, machines, handlers, etc., that produce circuits 120 and/orcircuits 210.

Step 2310 includes producing one or more transistor layers 1610 (e.g.,integrated circuit layers) to include multiple transistors.

Step 2320 includes fabricating one or more interconnect layers 1620 overthe transistor layer 1610 to connect the multiple transistors inparallel with each other. In one embodiment, sets of the multipletransistors are independent of each other until the source and drainnodes are connected to the conductive layer 1630. In such an embodiment,the sets of transistors are connected in parallel with each other afterthe nodes are connected to the conductive layer 1630.

Step 2340 includes fabricating a first conductive layer 1630 such asaluminum on the at least one interconnect layer 1620. The interconnectlayer(s) 1620 electrically couple the multiple transistors in thetransistor layer 1610 to the conductive layer 1630. By way of anon-limiting example, the conductive layer 1630 is a material such asaluminum having a first resistivity.

Step 2350 includes producing a portion of the conductive layer 1630 tobe a common circuit node (e.g., a common source node, a common drainnode, etc.) of the multiple transistors connected in parallel with eachother.

Step 2360 includes producing a dielectric layer 1640 over the conductivelayer 1630.

Step 2370 includes providing a field of conductive elements 126 in thedielectric layer 1640. As discussed below, the conductive elements 126in the dielectric layer 1640 will electrically connect the conductivelayer 1630 to the conductive layer 1650.

Step 2410 in FIG. 23 includes utilizing a metal such as copper tofabricate conductive layer 1650 over the dielectric layer 1640. Theconductive layer 1650 is electrically connected to conductive layer 1650via the multiple conductive elements 126 extending through thedielectric layer 1640. By way of a non-limiting example, in oneembodiment, the conductive layer 1650 is a material having a resistivityless than a resisitivity of material used to form the conductive layer1630.

Step 2420 includes producing a dielectric layer 1660 over the conductivelayer 1650.

Step 2430 includes providing multiple conductive elements (e.g., asource node 1680-1 and a drain node 168-2) in dielectric layer 1660 toelectrically connect conductive layer 1650 to a conductive path 140(e.g., conductive strip of metal) in a respective circuit packagedevice.

Note again that techniques herein are well suited for use in packagingelectronic parts such as those that provide switching capabilities.However, it should be noted that embodiments herein are not limited touse in such applications and that the techniques discussed herein arewell suited for other applications as well.

While this invention has been particularly shown and described withreferences to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the spirit and scope of the presentapplication as defined by the appended claims. Such variations areintended to be covered by the scope of this present application. Assuch, the foregoing description of embodiments of the presentapplication is not intended to be limiting. Rather, any limitations tothe invention are presented in the following claims.

We claim:
 1. A method comprising: receiving a semiconductor layerincluding multiple transistors; fabricating at least one interconnectlayer on the semiconductor layer to connect the multiple transistors inparallel with each other; fabricating a first conductive layer on the atleast one interconnect layer, the at least one interconnect layerelectrically coupling the multiple transistors to the first conductivelayer, the first conductive layer being a material having a firstresistivity; and electrically coupling a second conductive layer to thefirst conductive layer, the second conductive layer being a materialhaving a second resistivity, the second resistivity being less than thefirst resistivity; partitioning the first conductive layer to include asource node region and a drain node region, the source node region ofthe first conductive layer and the drain node region of the firstconductive layer being electrically isolated from each other, the sourcenode region of the first conductive layer electrically coupled to sourcenodes of the multiple transistors via connectivity through the multipleinterconnect layers, the drain node region of the first conductive layerelectrically coupled to drain nodes of the multiple transistors viaconnectivity through the multiple interconnect layers; partitioning thesecond conductive layer to include a first region and a second region,the first region and the second region in the second conductive layerbeing electrically isolated from each other; electrically coupling thefirst region of the second conductive layer to the source node region ofthe first conductive layer; and electrically coupling the second regionof the second conductive layer to the drain node region of the firstconductive layer.
 2. The method as in claim 1 further comprising:producing a portion of the first conductive layer to be a first commoncircuit node of the multiple transistors connected in parallel with eachother.
 3. The method as in claim 2 further comprising: electricallycoupling a portion of the second conductive layer to the first commoncircuit node, the electric coupling including multiple independentelectrically conductive paths from the first common circuit node to thesecond conductive layer.
 4. The method as in claim 1 further comprising:utilizing aluminum to fabricate the first conductive layer; andutilizing copper to fabricate the second conductive layer.
 5. The methodas in claim 1 further comprising: producing a dielectric layer betweenthe first conductive layer and the second conductive layer; andproviding multiple conductive elements in the dielectric layer toelectrically connect the first conductive layer to the second conductivelayer.
 6. The method as in claim 1 further comprising: providing a firstset of conductive links to electrically connect the source node regionin the first conductive layer to the region in the second conductivelayer; and providing a second set of conductive links to electricallyconnect the drain node region in the first conductive layer to thesecond region of the second conductive layer.
 7. The method as in claim6 further comprising: providing a leadframe package, the leadframepackage including a first conductive strip and a second conductivestrip; producing a first conductive pillar to provide electricalconnectivity between the first region of the second conductive layer andthe first conductive strip; and producing a second conductive pillar toprovide electrical connectivity between the second region of the secondconductive layer and the second conductive strip.
 8. The method as inclaim 1, wherein the first conductive layer and the second conductivelayer are disposed in a stack, the method further comprising: disposingthe first region over the source node region in the stack; and disposingthe second region over the drain node region in the stack.
 9. The methodas in claim 8 further comprising: producing a first electricallyconductive path to connect the first region to the source node region;producing a second electrically conductive path to connect the firstregion to the source node region; both the first electrically conductivepath and the second electrically conductive path providing connectivityfrom the first region through the source node region to a source node ofa transistor in the semiconductor layer; producing a third conductivepath connecting the second region to the drain node region; producing afourth electrically conductive path connecting the second region to thedrain node region; and both the third electrically conductive path andthe fourth electrically conductive path providing connectivity from thefirst region through the drain node region to a drain node of thetransistor in the semiconductor layer.
 10. The method as in claim 9further comprising: disposing a dielectric layer in the stack betweenthe first conductive layer and the second conductive layer; disposing afirst field of multiple spaced conductive elements in the dielectriclayer to electrically connect the source node region of the firstconductive layer to the first region of the second conductive layer, thefirst field of multiple spaced conductive elements including the firstelectrically conductive path and the second electrically conductivepath; and disposing a second field of multiple spaced conductiveelements in the dielectric layer to electrically connect the drain noderegion of the first conductive layer to the second region of the secondconductive layer, the second field of multiple spaced conductiveelements including the third electrically conductive path and the fourthelectrically conductive path.
 11. The method as in claim 1, wherein themultiple interconnect layers electrically connect a respective sourcenode of each of the multiple transistors in the semiconductor layer to asource node region of the first conductive layer; and wherein themultiple interconnect layers electrically connect a respective drainnode of each of the multiple transistors in the semiconductor layer tothe second portion of the first conductive layer.
 12. The method as inclaim 11 further comprising: producing a combination of the secondconductive layer, the first conductive layer, and the multipletransistors as a stack; producing a first portion of the secondconductive layer to reside over the source node region of the firstconductive layer, a first portion of the multiple transistors residingin the stack beneath the source node region of the first conductivelayer; and producing a second portion of the second conductive layer toreside over the drain node region of the first conductive layer, asecond portion of the multiple transistors residing in the stack beneaththe second portion of the first conductive layer.
 13. The method as inclaim 12, wherein the at least one interconnect layer connects a sourcenode of a first transistor in the first portion of the multipletransistors to the source node region; wherein the at least oneinterconnect layer connects a drain node of the first transistor to thedrain node region.
 14. The integrated circuit device as in claim 12,wherein the at least one interconnect layers electrically couple asource node of each respective transistor of the multiple transistors inthe semiconductor layer to the source node region of the firstconductive layer; and wherein the multiple interconnect layerselectrically couple a drain node of each respective transistor of themultiple transistors in the semiconductor layer to the drain node regionof the first conductive layer.
 15. The method as in claim 1, wherein thefirst conductive layer and the second conductive layer are part of astack, the first region and the second region disposed adjacent to eachother in the second conductive layer, the source node region and thedrain node region disposed adjacent to each other in the firstconductive layer, the first region disposed above the source node regionin the stack, the second region disposed above the drain node region inthe stack.
 16. A method comprising: producing an integrated circuit toinclude: a semiconductor layer including multiple transistors; multipleinterconnect layers connecting the multiple transistors in parallel; afirst conductive layer electrically coupled to the multiple transistorsvia the multiple interconnect layers, the first conductive layer being amaterial having a first resistivity; a second conductive layerelectrically coupled to the first conductive layer, the secondconductive layer being a material having a second resistivity, thesecond resistivity being less than the first resistivity; and the firstconductive layer disposed between the semiconductor layer and the secondconductive layer, the first conductive layer providing electricalconnectivity between the multiple transistors connected in parallel andthe second conductive layer; wherein a first portion of the firstconductive layer is a first common circuit node of the multipletransistors connected in parallel with each other; wherein a secondportion of the first conductive layer is a second common circuit node ofthe multiple transistors connected in parallel with each other; whereinthe first portion of the first conductive layer and the second portionof the first conductive layer are electrically isolated from each other;wherein a first portion of the second conductive layer is electricallycoupled to the first portion of the first conductive layer; wherein asecond portion of the second conductive layer is electrically coupled tothe second portion of the first conductive layer; wherein the firstportion of the second conductive layer and the second portion of thesecond conductive layer are electrically isolated from each other; adielectric layer disposed between the first conductive layer and thesecond conductive layer; a first field of multiple spaced conductiveelements disposed in the dielectric layer to electrically connect thefirst portion of the first conductive layer to the first portion of thesecond conductive layer; a second field of multiple spaced conductiveelements disposed in the dielectric layer to electrically connect thesecond portion of the first conductive layer to the second portion ofthe second conductive layer; wherein the multiple interconnect layerselectrically connect a respective source node of each of the multipletransistors in the semiconductor layer to the first portion of the firstconductive layer; wherein the multiple interconnect layers electricallyconnect a respective drain node of each of the multiple transistors inthe semiconductor layer to the second portion of the first conductivelayer; wherein a combination of the second conductive layer, the firstconductive layer, and the multiple transistors form a stack; wherein thefirst portion of the second conductive layer resides over the firstportion of the first conductive layer, a first portion of the multipletransistors residing in the stack beneath the first portion of the firstconductive layer; and wherein the second portion of the secondconductive layer resides over the second portion of the first conductivelayer, a second portion of the multiple transistors residing in thestack beneath the first portion of the first conductive layer.
 17. Themethod as in claim 16, wherein the first conductive layer is aluminumand the second conductive layer is copper.
 18. The method as in claim 16further comprising: installing the integrated circuit in a lead framepackage, the leadframe package including a first conductive strip and asecond conductive strip disposed in parallel, wherein a first conductivecontact provides electrical connectivity between the first portion ofthe second conductive layer and the first conductive strip, and whereina second conductive contact provides electrical connectivity between thesecond portion of the second conductive layer and the second conductivestrip.
 19. The method as in claim 16 further comprising: fabricating thefirst portion of the first conductive layer to reside adjacent to thesecond portion of the first conductive layer; and fabricating the firstportion of transistors to reside adjacent to the second portion of thetransistors in the semiconductor layer.